The pressure vessel of the air compressor has reached its design service life. Can it still be used?

The meaning of the design service life for pressure vessels in air compressors

Before determining whether continued use is permissible, it is first necessary to clarify the concept of “design life.” For pressure vessels such as air‑storage tanks that are part of an air‑compressor system, the design life refers to the period during which the equipment can be operated safely under normal conditions, as specified in the design. It does not represent an absolute end‑of‑life threshold; rather, it is a safety‑based service life provided by the manufacturer, taking into account factors such as material fatigue and corrosion rates.

Can it be used directly after the design service life has expired?

The answer isCannot be used directly anymore.According to the relevant regulations on the safety management of special equipment, once a pressure vessel reaches its design service life, its material properties and structural strength may undergo unforeseeable degradation. If it is put back into service without undergoing professional assessment and inspection, it will pose significant safety risks. Therefore, upon reaching its expiration date, the vessel must be immediately taken out of service, and the subsequent inspection and evaluation procedures must be initiated.

Compliance procedures for continued use upon expiration

If an enterprise wishes to continue using the pressure vessel, it must operate in strict accordance with the safety technical specifications for special equipment. Typically, the following procedures and conditions must be met:

• Apply for a comprehensive inspection: User units shall apply to a qualified special equipment inspection agency for periodic inspections, particularly comprehensive inspections of equipment that has reached its expiration date.
• Safety Condition AssessmentThe inspection agency will conduct a comprehensive examination of the vessel’s material, wall thickness, welds, safety accessories, and other relevant components, and assign a safety condition rating.
• Issue an inspection reportOnly when the inspection results meet the specified requirements and the period and conditions for continued use have been clearly defined does the equipment possess the technical basis for continued operation.
• Handle the registration amendment: The user shall submit the inspection report and other relevant documentation to the local special equipment safety supervision and administration authority to apply for the amendment or extension of the use registration certificate.

Methods for handling failures in inspection

If, during a comprehensive inspection, the inspection agency identifies serious defects in a pressure vessel—such as extensive corrosion, severe material degradation, or an unsatisfactory safety condition rating—the equipment shallMust be compulsorily scrappedThe using unit shall subject it to destructive disposal to prevent its re-entry into the circulation and use stages, and promptly submit cancellation procedures to the special equipment regulatory authority.

Daily Management and Safety Recommendations

To ensure the long-term safe operation of air compressor pressure vessels, the following points should be observed in daily management:

• Regular blowdown: Routinely perform daily drainage of the gas storage tank to reduce internal water accumulation and impurities, thereby lowering the corrosion rate of the inner wall.
• Verify safety accessoriesEnsure that safety valves and pressure gauges are within their calibration validity period, and conduct regular manual relief tests.
• Standardized operationsOperation beyond the specified temperature and pressure limits is strictly prohibited; equipment must be protected from severe impact due to alternating loads.
• Establish a file: Improve the technical documentation for equipment, recording the details of each inspection, maintenance, and routine patrol to ensure that all activities are traceable and verifiable.